Police said Christopher Berry, 32, and Christopher Cash, 29, were charged with "providing prejudicial information to a foreign state, China".
They are due to appear at Westminster Magistrates' Court on Friday.
Police allege the two men collected, recorded or communicated information "prejudicial to the safety or interests of the state" and violated the Official Secrets Act between late 2021 and February 2023.
"This has been an extremely complex investigation into what are very serious allegations," said Dominic Murphy, head of the Metropolitan Police counterterrorism command.
The Sunday Times reported last year that Cash was arrested for spying for Beijing.
The report said he was a parliamentary researcher who worked with senior lawmakers from the governing Conservatives, including Alicia Kearns, who now heads the powerful Foreign Affairs Committee, and her predecessor in that role, Tom Tugendhat, who is now security minister.
The newspaper said the suspect held a pass that allows full access to the Parliament buildings, issued to MPs, staff and journalists after security vetting.
British Prime Minister Rishi Sunak said last year he raised the issue with Chinese Premier Li Qiang, saying he voiced "very strong concerns" about interference in British democracy.
At the time, the Chinese embassy issued a statement calling the allegations fabricated.
Also on Monday, three people were arrested in Germany on suspicion of spying for China and arranging to transfer information on technology with potential military uses.
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